ARLINGTON, Texas — For the players who have a locker at Dove Valley, for John Fox and his coaching staff, for John Elway and his front office, here's hoping they don't suffer from insecurity.

This is not so much about the Denver Broncos. This is about Peyton Manning. It was Manning's quarterback brilliance that beat the Dallas Cowboys, 51-48, in a Texas-style shootout here Sunday before a crowd of — get this — 92,758 at the dazzling sports castle that is AT&T Stadium.

And nothing but Manning.

Denver's defense provided little challenge to the twirling dervish, pinpoint passer that was Cowboys quarterback Tony Romo. So bad were the Broncos on defense, Manning was behind two touchdowns before he got a chance to finish his first drive.

The Broncos were so bad early, they had but one chance to avoid their first loss. So what else is new? From 14 points down, Manning on his next five possessions threw four touchdown passes and ran in for another score on a perfectly executed hidden-ball keeper to put the Broncos up 15 points a few minutes into the second half.

In a wild back-and-forth second half, Matt Prater's 28-yard field goal provided the winning points as the clock ran out. Linebacker Danny Trevathan set up the winning score with an interception at the Cowboys' 24.

During the week leading up to the game, Cowboys veteran linebacker Ernie Sims was quoted as saying he was sick of hearing about Manning.

Hey Ernie: Peyton Manning, Peyton Manning, Peyton Manning.

The Broncos themselves better get used to hearing how Manning is single-handedly carrying them. Sure, somebody has to block for him, and catch his passes. And Manning can't play defense, even if he did show he can run around left end.

But the Broncos are 5-0 primarily because Manning started his season with 20 touchdown passes and zero interceptions. He threw his first pick of the season into the Cowboy stadium glare with seconds left in the third quarter.

But after Romo rallied the Cowboys to a 48-41 lead midway through the fourth quarter with a more athletic, even balletic performance, Manning calmly continued his carving of the Dallas defense, going 5 of 5 for 77 yards to set up a 1-yard touchdown run by Knowshon Moreno to make it 48-48.

That left 2:39 remaining in regulation, Dallas ball. And finally, Romo reverted back to the Romo that so many love to hate. He cracked. Deep in his own territory, Romo threw into a double coverage. Trevathan — carted off the field during practice Wednesday with little more than a banged up knee, as it turned out — made a diving interception at the Cowboys' 24.

Manning threw a 13-yard completion to Demaryius Thomas, who made a terrific catch, to set up a first down at the Dallas 11 with less than 2 minutes remaining.

From there the Broncos did just enough to play keepaway from Romo and maneuver to give Prater a chip shot field. Prater had pelted field goals of 48 and 50 yards earlier.

Von Miller was supposed to be the Broncos' second-best player. Remember him? He has been suspended from the first five games and the Broncos are 5-0. Champ Bailey seems certain to have his bust bronzed in Canton some day. The Broncos are 5-0 without him.

Knowshon Moreno gets some air while running past J.J. Wilcox of the Cowboys. More photos. (AAron Ontiveroz, The Denver Post)

Left tackle is supposedly the second-most important position on offense. The Broncos had a great left tackle in Ryan Clady until he suffered a season-ending foot injury in game 2. The Broncos are 3-0, averaging 42.3 points, without him.

A skeptic might say Manning has the best receiving group in the NFL to aid his quarterback play. Those same skeptics would agree Demaryius Thomas and Wes Welker are the two best in Manning's pass-catching group. Thomas and Welker did not have a catch in the first half.

Manning instead threw two touchdown passes to tight end Julius Thomas, who the Cowboys couldn't cover if they were given a long lasso, and one to Eric Decker, whose fumble after making a first-down catch is the only reason why the Broncos only scored on five of their first six possessions.

With Miller and Bailey missing, two of the Broncos' best defensive players have been linebacker Wesley Woodyard and cornerback Chris Harris. Both sustained injuries in the first half and didn't return.

Manning doesn't throw long unless he has to. On his four touchdown passes, he didn't have to, as they went for 4, 2, 9 and 2 yards. His touchdown run was for no more than an inch. Manning faked the hand off to tailback Montee Ball, then took off around left end. Cowboys right defensive end DeMarcus Ware crashed into the middle where Ball didn't have the ball.